The present invention relates to an ink-jet recording apparatus and, particularly, to an improved ink-jet recording apparatus of a type, in which ink droplets are ejected from a nozzle and impinge on the recording medium to form dots thereon, and the position of the record is affected by the change in the relative speed between the nozzle and the recording medium.
It is important for an ink-jet recording apparatus to make a dot record of ink droplets accurately at a specified position on the recording medium. Particularly, in case of color recording, ink droplets ejected from more than one nozzle must produce dots accurately at specified positions on the recording medium.
Ink-jet recording apparatus recording information on the recording paper which is rotated on the drum are disclosed in U.S. Pat. No. 3,928,718 by Syoji Sagae et al., and U.S. Pat. No. 3,999,188 by Takahiro Yamada et al. In these apparatus, ink droplets are ejected from the nozzle at a fixed time interval, and therefore if the rotational speed of the drum varies, the dots are not recorded on the correct position of the recording paper, resulting in an uneven pitch of dots. These ink-jet recording apparatus are capable of recording images in color through the arrangement of more than one nozzle for various colors in the circumferential direction of the drum. However, when a certain pattern of image is intended to produce using a plurality of nozzles, recorded patterns by the nozzles would be out of alignment with each other unless each nozzle produces a pattern respectively at a correct position accurately. A possible cause of such a faulty print result is induced by the fluctuation of the drum speed.